title: Investigation of platelet-neutrophil interactions in whole blood by flow cytometry.
abstract: Evidence is increasing that platelets can initiate and propagate inflammatory processes by interacting with leucocytes and the vascular endothelium. Platelets have been shown to bind to neutrophils, existing as platelet/neutrophil complexes (PNC) within the circulation. We describe a simple flow cytometric method for assessing and investigating platelet interactions with neutrophils in small volumes of whole blood. Twenty-five percent (sd 6%) of circulating neutrophils from healthy adults were associated with platelets. Formation of these platelet-neutrophil complexes was CD62P (P-selectin) and divalent cation dependent. Platelet activation (with ADP or thrombin) caused a rapid and sustained rise in %PNC which differed from the pattern of free platelet activation as assessed by CD62P expression. F-met-leu-phe induced neutrophil activation but did not increase the percentage PNC. Platelet activation also caused increased neutrophil CD11b/CD18 expression which was most marked on neutrophils complexed with platelets. This straightforward technique is simple, reproducible, and allows assessment of platelet-neutrophil interactions and activation of neutrophils. It may also provide a method for estimating platelet activation in whole blood.
authors.affiliation: Department of Immunobiology, Institute of Child Health, London, UK. m.peters@ich.ucl.ac.uk
authors.forename: M J
authors.initials: MJ
authors.lastname: Peters
authors.forename: R S
authors.initials: RS
authors.lastname: Heyderman
authors.forename: D J
authors.initials: DJ
authors.lastname: Hatch
authors.forename: N J
authors.initials: NJ
authors.lastname: Klein
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000166:cytology* / Q000187:drug effects; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology*; D019007:P-Selectin / Q000096:biosynthesis; D015539:Platelet Activation
chemical_list: D019007:P-Selectin; D009240:N-Formylmethionine Leucyl-Phenylalanine